This invention relates generally to remote diagnostic monitoring of rotating machinery such as, but not limited to, gas turbines and more particularly to systems and methods for collecting and analyzing data used for such diagnostic monitoring.
Gas turbines are used for a variety of applications such as driving an electric generator in a power generating plant or propelling a ship or an aircraft. In any application, gas turbines are routinely subject to various maintenance procedures as part of their normal operation. To aid in the provision of such maintenance services, monitoring systems are often employed to provide diagnostic monitoring of the gas turbine. These systems commonly include performance monitoring equipment that collects relevant trend and fault data used for diagnostic trending. In diagnostic trend analysis, certain process data (such as exhaust gas temperature, fuel flow, rotor speed and the like) that are indicative of overall gas turbine performance and/or condition are compared to a parametric baseline for the gas turbine. Any divergence of the raw trend data from the parametric baseline may be indicative of a present or future condition that requires maintenance. Such data can be recorded locally and accessed later by maintenance personnel or, alternatively, can be transmitted to a remote location so that a number of gas turbines can be remotely monitored at a central site.
Gas turbines, like all rotating machinery, are subject to vibrations due to causes such as rotor imbalance, misalignment of components, and worn or defective bearings. Thus, it is useful to monitor vibration and/or other dynamic gas turbine data in addition to the static gas turbine process data discussed above. However, transmitting dynamic signal data from the field units to the central site in a remote monitoring system can be difficult. At present, remote monitoring of process and dynamic data is typically accomplished by using two computers on-site: one for collecting and processing the dynamic data and another for collecting and processing the process data.
One drawback with this approach is the cost of providing and maintaining two separate computers. Another is an inability to analyze the dynamic and process signals in a time coherent manner. When analyzing such data, the ability to review the dynamic and process signals on a simultaneous or time coherent basis provides a better understanding of the overall gas turbine condition. But the current two-computer system does not provide for time coherent review.
Accordingly, it would be desirable to be able to remotely monitor dynamic and process signals at the same time using a single computer system.
The above-mentioned need is met by the present invention which provides a remote monitoring system having a central computer system and at least one data acquisition unit for collecting data from a machine to be monitored. The data acquisition unit includes an on-site computer system having a central processor and an auxiliary processor. The data acquisition unit further includes a means for generating a process data signal and a means for generating a dynamic data signal. The process data signal is fed to the central processor and the auxiliary processor, and the dynamic data signal is fed to the auxiliary processor. A communication link connects the central computer system and the on-site computer system.
The present invention and its advantages over the prior art will become apparent upon reading the following detailed description and the appended claims with reference to the accompanying drawings.